Brittle Star?? what is he eating?

I purchased some live rock with polopys and identified a hitch hiker as a brittle star. He rarely comes out 100% but i do see his tentacles. What does he eat? and is he eating the polopys that are on the rock?? it looks like my rock and the polopys aren't as healthy as they should be but my reef test say everything is fine. Any advice?

 

is it big ? or little? cuz I have micro brittle stars and I don't believe they are bad and I see their little arms sticking out too

 

he's small he hardly comes out 100% from the rock. What do they eat? I heard they eat coral and i'm worried he's eating the coral off the rock.

 

I think they are okay, but maybe some aren't maybe someone else will chime in who knows more about them.

 

Congrats! Serpent and brittle starfish are scavengers, they will each whatever is on the sand bed. You can target feed them too. I have a serpent starfish & it is so cool.. When I feed, it comes right out & boy does it move.. It won't eat your coral, unless it's dead or decaying of course..

 

As mentioned, these are a good addition to your clean up crew. Fun to watch as well. They can get 8-10 inches and can move rather quickly. Usually when you are feeding the tank they will pop out and wrestle with a snail/crab for a piece of food that landed on the sand/rock. They are very hardy and multiply well in a stable environment. Pull out a flash light a couple hours after lights out and you may see it (and perhaps more) savaging about the sand – excellent sand shifters btw.

 

Sounds like a mini-brittle star, a common hitchhider. The big ones are two inches tip-to-tip, good mini cleanup-crew. They eat detritus.
They stay small and will attempt to collect food by waving just their arms out of the holes in the rock. They don't come all the way out too often, I find more under rocks, occasionally they'll be scavenging in a ball of cheato.

The mini-brittles won't eat polyps, but occasionally a mini regular star will. More likely the polyps are somewhat unhappy because they are in new tank with different lighting, different waterflow, different parameters, etc. If after a few days they aren't emerging, try moving them to more/less light, more or less flow, etc.